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Fuel Pressure Test

Special Tools Required 

  1. Make sure you have the anti-theft codes for the radio and the navigation system (if equipped), then write down the frequencies for the radio's preset buttons.
  2. Disconnect the negative cable from the battery.
  3. Remove the fuel fill cap.
  4. Place a wrench on the fuel pulsation damper (A) at the fuel rail
    Fig 1: Placing A Wrench On Fuel Pulsation Damper
    G01511727Courtesy of AMERICAN HONDA MOTOR CO., INC.
  5. Place a rag or shop towel (B) over the fuel pulsation damper.
  6. Slowly loosen the fuel pulsation damper one complete turn.
  7. Remove the fuel pulsation damper from its fitting, and attach the fuel pressure gauge attachment.
    Fig 2: Removing Fuel Pulsation Damper From Fitting
    G01511728Courtesy of AMERICAN HONDA MOTOR CO., INC.
  8. Attach the fuel pressure gauge.
    Fig 3: Attaching Fuel Pressure Gauge ('99-01 models)
    G01511729Courtesy of AMERICAN HONDA MOTOR CO., INC.
    Fig 4: Attaching Fuel Pressure Gauge ('02-04 models)
    G01511730Courtesy of AMERICAN HONDA MOTOR CO., INC.
  9. '99-01 models: 

    Disconnect the vacuum hose (A) of the fuel pressure regulator, and pinch it closed with a clamp (B).

  10. Reconnect the negative cable to the battery, then start the engine and let it idle.
    • If the engine starts, go to step  12 ('99-01 models) or step  16 ('02-04 models).
    • If the engine does not start, go to step 11.
  11. Check to see if the fuel pump is running: listen to the injector rails underneath the intake manifold cover while an assistant turns the ignition switch ON (II). You should hear the fuel flow through the injector rails for about 2 seconds when the ignition turned ON (II).
    • If the pump runs, go to step 12 ('99-01 models) or step  16 ('02-04 models).
    • If the pump does not run, test the fuel pump. See Fuel Pump Test .
  12. '99-01 models: 

    Read the pressure gauge (with the fuel pressure regulator vacuum hose disconnected and clamped). The pressure should be 300-340 kPa (3.0-3.5 kgf/cm2 , 43-49 psi).

    • If the pressure is OK and engine is running, go to step 13. If not running, repair the cause, then continue this test.
    • If the pressure is out of spec, go to step  14.
  13. '99-01 models: 

    With the engine running, reconnect the vacuum hose and read the gauge again. The pressure should be 240-300 kPa (2.5-3.0 kgf/cm2 , 36-43 psi).

    • If the fuel pressure is OK, the test is complete. Go to step  15.
    • If the pressure is out of spec, go to step 14.
  14. '99-01 models: 

    Disconnect the vacuum hose from the pressure regulator again while you watch the pressure gauge. The pressure should increase when you disconnect the hose.

    • If the pressure did not increase, replace the fuel pressure regulator, see Fuel Pressure Regulator Replacement  and recheck the fuel pressure.
    • If the pressure increased, and all your readings were within spec, go to step 15.
    • If the pressure increased, but your readings were out of spec, check for these problems:
    • If the pressure is too low, check for a clogged fuel filter and for leaks in the fuel lines.
    • If the pressure is too high, check for a pinched or clogged fuel return hose or line.
    • Fuel rail restrictions.
  15. '99-01 models: 

    Reconnect the vacuum hose, remove the pressure gauge, and reinstall the fuel pulsation damper with a new washer. Tighten the fuel pulsation damper to 22 N.m (2.2kgf.m, 16 lbf.ft).

    NOTE: Disassemble and clean the fuel pressure gauge attachment thoroughly after use.
  16. '02-04 models: 

    Read the pressure gauge. The pressure should be 290-330 kPa (2.9-3.4 kgf/cm2 , 42-48 psi).

    • If the pressure is OK and engine is running, the test is complete. If the engine is not running, repair the cause, then continue this test.
    • If the pressure is too high, check for a pinched or clogged fuel return hose or line.
    • If the pressure is too low, check for a clogged fuel filter and for leaks in the fuel lines.
    • If the pressure is out of spec and the fuel lines are OK, replace the pressure regulator. See Fuel Pressure Regulator Replacement .
  17. '02-04 models: 

    Remove the pressure gauge, and reinstall the fuel pulsation damper with a new washer. Tighten the fuel pulsation damper to 22 N.m (2.2kgf.m, 16 lbf.ft).

    NOTE: Disassemble and clean the fuel pressure gauge attachment thoroughly after use.
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